filedircontext.java

业界著名的tomcat服务器的最新6.0的源代码。

    /**
     * Return a context-relative path, beginning with a "/", that represents
     * the canonical version of the specified path after ".." and "." elements
     * are resolved out.  If the specified path attempts to go outside the
     * boundaries of the current context (i.e. too many ".." path elements
     * are present), return <code>null</code> instead.
     *
     * @param path Path to be normalized
     */
    protected String normalize(String path) {

    String normalized = path;

    // Normalize the slashes and add leading slash if necessary
    if (File.separatorChar == '\\' && normalized.indexOf('\\') >= 0)
        normalized = normalized.replace('\\', '/');
    if (!normalized.startsWith("/"))
        normalized = "/" + normalized;

    // Resolve occurrences of "//" in the normalized path
    while (true) {
        int index = normalized.indexOf("//");
        if (index < 0)
        break;
        normalized = normalized.substring(0, index) +
        normalized.substring(index + 1);
    }

    // Resolve occurrences of "/./" in the normalized path
    while (true) {
        int index = normalized.indexOf("/./");
        if (index < 0)
        break;
        normalized = normalized.substring(0, index) +
        normalized.substring(index + 2);
    }

    // Resolve occurrences of "/../" in the normalized path
    while (true) {
        int index = normalized.indexOf("/../");
        if (index < 0)
        break;
        if (index == 0)
        return (null);  // Trying to go outside our context
        int index2 = normalized.lastIndexOf('/', index - 1);
        normalized = normalized.substring(0, index2) +
        normalized.substring(index + 3);
    }

    // Return the normalized path that we have completed
    return (normalized);

    }


    /**
     * Return a File object representing the specified normalized
     * context-relative path if it exists and is readable.  Otherwise,
     * return <code>null</code>.
     *
     * @param name Normalized context-relative path (with leading '/')
     */
    protected File file(String name) {

        File file = new File(base, name);
        if (file.exists() && file.canRead()) {

        	if (allowLinking)
        		return file;
        	
            // Check that this file belongs to our root path
            String canPath = null;
            try {
                canPath = file.getCanonicalPath();
            } catch (IOException e) {
            }
            if (canPath == null)
                return null;

            // Check to see if going outside of the web application root
            if (!canPath.startsWith(absoluteBase)) {
                return null;
            }

            // Case sensitivity check
            if (caseSensitive) {
                String fileAbsPath = file.getAbsolutePath();
                if (fileAbsPath.endsWith("."))
                    fileAbsPath = fileAbsPath + "/";
                String absPath = normalize(fileAbsPath);
                if (canPath != null)
                    canPath = normalize(canPath);
                if ((absoluteBase.length() < absPath.length())
                    && (absoluteBase.length() < canPath.length())) {
                    absPath = absPath.substring(absoluteBase.length() + 1);
                    if ((canPath == null) || (absPath == null))
                        return null;
                    if (absPath.equals(""))
                        absPath = "/";
                    canPath = canPath.substring(absoluteBase.length() + 1);
                    if (canPath.equals(""))
                        canPath = "/";
                    if (!canPath.equals(absPath))
                        return null;
                }
            }

        } else {
            return null;
        }
        return file;

    }


    /**
     * List the resources which are members of a collection.
     *
     * @param file Collection
     * @return Vector containg NamingEntry objects
     */
    protected ArrayList list(File file) {

        ArrayList entries = new ArrayList();
        if (!file.isDirectory())
            return entries;
        String[] names = file.list();
        if (names==null) {
            /* Some IO error occurred such as bad file permissions.
               Prevent a NPE with Arrays.sort(names) */
            log.warn(sm.getString("fileResources.listingNull",
                                  file.getAbsolutePath()));
            return entries;
        }

        Arrays.sort(names);             // Sort alphabetically
        if (names == null)
            return entries;
        NamingEntry entry = null;

        for (int i = 0; i < names.length; i++) {

            File currentFile = new File(file, names[i]);
            Object object = null;
            if (currentFile.isDirectory()) {
                FileDirContext tempContext = new FileDirContext(env);
                tempContext.setDocBase(file.getPath());
                tempContext.setAllowLinking(getAllowLinking());
                tempContext.setCaseSensitive(isCaseSensitive());
                object = tempContext;
            } else {
                object = new FileResource(currentFile);
            }
            entry = new NamingEntry(names[i], object, NamingEntry.ENTRY);
            entries.add(entry);

        }

        return entries;

    }


    // ----------------------------------------------- FileResource Inner Class


    /**
     * This specialized resource implementation avoids opening the IputStream
     * to the file right away (which would put a lock on the file).
     */
    protected class FileResource extends Resource {


        // -------------------------------------------------------- Constructor


        public FileResource(File file) {
            this.file = file;
        }


        // --------------------------------------------------- Member Variables


        /**
         * Associated file object.
         */
        protected File file;


        /**
         * File length.
         */
        protected long length = -1L;


        // --------------------------------------------------- Resource Methods


        /**
         * Content accessor.
         *
         * @return InputStream
         */
        public InputStream streamContent()
            throws IOException {
            if (binaryContent == null) {
                inputStream = new FileInputStream(file);
            }
            return super.streamContent();
        }


    }


    // ------------------------------------- FileResourceAttributes Inner Class


    /**
     * This specialized resource attribute implementation does some lazy
     * reading (to speed up simple checks, like checking the last modified
     * date).
     */
    protected class FileResourceAttributes extends ResourceAttributes {


        // -------------------------------------------------------- Constructor


        public FileResourceAttributes(File file) {
            this.file = file;
        }

        // --------------------------------------------------- Member Variables


        protected File file;


        protected boolean accessed = false;


        protected String canonicalPath = null;


        // ----------------------------------------- ResourceAttributes Methods


        /**
         * Is collection.
         */
        public boolean isCollection() {
            if (!accessed) {
                collection = file.isDirectory();
                accessed = true;
            }
            return super.isCollection();
        }


        /**
         * Get content length.
         *
         * @return content length value
         */
        public long getContentLength() {
            if (contentLength != -1L)
                return contentLength;
            contentLength = file.length();
            return contentLength;
        }


        /**
         * Get creation time.
         *
         * @return creation time value
         */
        public long getCreation() {
            if (creation != -1L)
                return creation;
            creation = file.lastModified();
            return creation;
        }


        /**
         * Get creation date.
         *
         * @return Creation date value
         */
        public Date getCreationDate() {
            if (creation == -1L) {
                creation = file.lastModified();
            }
            return super.getCreationDate();
        }


        /**
         * Get last modified time.
         *
         * @return lastModified time value
         */
        public long getLastModified() {
            if (lastModified != -1L)
                return lastModified;
            lastModified = file.lastModified();
            return lastModified;
        }


        /**
         * Get lastModified date.
         *
         * @return LastModified date value
         */
        public Date getLastModifiedDate() {
            if (lastModified == -1L) {
                lastModified = file.lastModified();
            }
            return super.getLastModifiedDate();
        }


        /**
         * Get name.
         *
         * @return Name value
         */
        public String getName() {
            if (name == null)
                name = file.getName();
            return name;
        }


        /**
         * Get resource type.
         *
         * @return String resource type
         */
        public String getResourceType() {
            if (!accessed) {
                collection = file.isDirectory();
                accessed = true;
            }
            return super.getResourceType();
        }

        
        /**
         * Get canonical path.
         * 
         * @return String the file's canonical path
         */
        public String getCanonicalPath() {
            if (canonicalPath == null) {
                try {
                    canonicalPath = file.getCanonicalPath();
                } catch (IOException e) {
                    // Ignore
                }
            }
            return canonicalPath;
        }
        

    }


}